> ## Documentation Index
> Fetch the complete documentation index at: https://docs.blujay.io/llms.txt
> Use this file to discover all available pages before exploring further.

# UNSUPPORTED_ATTACHMENT_TYPE

> Unsupported file type

| HTTP status | Retryable |
| - | - |
| `415` | No |

## What happened

The file type is not supported, or not supported by the service the message is going out on.

## How to fix it

Send a supported type. iMessage accepts most safe file types; RCS and SMS/MMS accept images and videos.

## Example response

An illustrative example. The `message` wording and the contents of `details` vary; branch on `error.code`.

```json theme={null}
{
  "status": "error",
  "error": {
    "code": "UNSUPPORTED_ATTACHMENT_TYPE",
    "message": "Unsupported file type",
    "type": "validation",
    "http_status": 415,
    "retryable": false,
    "doc_url": "https://docs.blujay.io/errors/unsupported-attachment-type",
    "details": []
  },
  "trace_id": "trc_8f2a1c0e4b7d",
  "timestamp": "2026-10-14T17:30:48.000Z"
}
```

## Still stuck?

Email [support@blujay.io](mailto:support@blujay.io) with the `trace_id` from the error response. See [Errors](/errors.md) for the response format.


This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.